An additional fifty eligible subjects will be interviewed by the end of the data collection phase. This would give a total of 739 completed interviews of nineteen more than initially estimated. The specifics of the work remaining involve: identifying and interviewing all remaining ovarian cancer cases diagnosed in May and June of 1981; identifying and interviewing one control subject for each of the cases processed identified above; obtaining representative microscopic slides, pathology reports, and operative reports for all cases, and arranging for histologic review by a consulting pathologist; obtaining corroboratory data (e.g., documentation of hormone usage) on all cases and controls interviewed after June 1, 1981; coding and processing interview-based and corroboratory data and editing the data for computer file entry; reviewing and analyzing the final data set; and preparation of a final report.